22 October 1955: At Edwards Air Force Base, in the high desert of southern California, Republic Aviation Corporation test pilot Russell M. (“Rusty”) Roth took the first of two prototype YF-105A-1-REs, serial number 54-098, for its first flight.
Though equipped with an under-powered Pratt & Whitney J57-P-25 interim engine, the new airplane was able to reach Mach 1.2 in level flight.
Aerodynamic improvements to the engine intakes and redesign of the fuselage to incorporate the drag-reducing “area rule,” along with the more powerful J75-P-5 turbojet engine allowed the production model F-105B to reach Mach 2.15.
The Pratt & Whitney Turbo Wasp JT3C (J57-P-25) was a two-spool axial-flow turbojet engine with a 16-stage compressor section (9 low- and 7 high-pressure stages) and a 3-stage turbine (1 high- and 2 low-pressure stages). The J57-P-25 had a Normal Power rating of 8,700 pounds of thrust (38.700 kilonewtons), and at Military Power produced 10,200 pounds of thrust (45.372 kilonewtons) (30-minute limit). The Maximum Power rating was 16,000 pounds of thrust (71.172 kilonewtons) with afterburner (5-minute limit). The J57-P-25 was 22 feet, 3.1 inches (6.784 meters) long, 3 feet, 3.8 inches (1.011 meters) in diameter, and weighed 5,120 pounds (2,322 kilograms).
The YF-105A’s wings were swept 45° at 25% chord. The angle of incidence was 0° and there was no twist. The wings had 3° 30′ anhedral. The total wing area was 385 square feet (35.8 square meters).
During testing, the prototype’s maximum speed was 770 knots (886 miles per hour (1,426 kilometers per hour) at 35,000 feet (10,668 meters)—Mach 1.34—and 676 knots (778 miles per hour/1,252 kilometers per hour) at Sea Level—Mach 1.02. The YF-105A’s service ceiling was 52,050 feet (15,865 meters). It’s combat radius was 950 nautical miles (1,093 statute miles/1,759 kilometers), and the maximum ferry range was 2,321 nautical miles (2,671 statute miles/4,298 kilometers).
The Thunderchief was armed with a General Electric T171E2 (M61) 20 mm six-barrel rotary cannon with 1,030 rounds of ammunition. 8,000 pounds (3,629 kilograms) of bombs could be carried in an internal bomb bay or on external hardpoints. A single free-fall B28IN variable-yield thermonuclear bomb could be carried in the bomb bay.
On 16 December 1955, YF-105A 54-098 made an emergency landing at Edwards AFB after one of its main landing gear assemblies was torn off when it failed to retract during a high speed flight. The pilot, Rusty Roth, was severely injured, but he survived. The prototype was shipped back to Republic for repair, but the cost was determined to be prohibitive.
Though designed for air-to-ground attack missions, F-105s are officially credited with 27.5 victories in air combat.
833 Thunderchiefs were built by Republic between 1955 and 1964. 334 of those were lost to enemy action during the Vietnam War. The F-105 remained in service with the United States Air Force until 1980, and with a few Air National Guard units until 1983.
© 2018, Bryan R. Swopes
My Mom was a bucket at Republic Avaition and built the 105
God bless her.
my father flew 2 tours in Vietnam with over 2500 hours logged. this was his favorite plane he would say “It brought me home”. He had 32 years in Air Force flying 105 , F4 ,and F16.
My hat is off to your father thanks for his service and bravery
As an exchange officer from the RAF I was privileged to spend over 700 hours in the Thud and I have unswerving admiration for the aircraft and those friends and colleagues who were called to the colours in SEA but less respect for those in Washington who misjudged the politics.
I went through USAF pilot training in 1968. We had an instructor who had a patch on his jacket and flight suit that read, “100 Missions – North Vietnam – F-105”. I didn’t know much about the 105 or the N Vietnam missions they were flying until I got to Vietnam in 1970. I can tell you that for USAF pilots, when you saw that patch, you knew you were in the presence of someone who had done something very special and survived.
In my opinion, there was no more dangerous mission than those the F-105 flew into N Vietnam. In fact there was a squadron in Thailand (don’t recall which one) that over time lost 100% of the airplanes that were assigned to it, plus some of their replacements. 50% of the pilots were shot down, with most of those captured or killed in action. In other words, you had a 50% chance that you would not get your 100 counters. Those are not good odds, but they went when called on to fly the mission.
In 1972, I flew B-52’s out of Utapao, Thailand. Many of our missions were to N Vietnam and the Hanoi area, and were it not for the Wild Weasels (2-seat F-105’s) that detected and attacked the SAM sites, we would have lost many more airplanes than we did.
My utmost respect to all F-105 drivers.
Thank you, Max.
Well stated, Jock. Thanks for your service. Per Ardua Ad Astra.
My Dad help build this Great aircraft
Had a Thud come back from the range at Wheelus [64-5]with a “Engine would not go over 103% in burner’? C Chief put on Bunny Suit and crawled down intake. 1-2 minutes later CC called down and stated LT your best get up here. Donned B Suit and crawled down intake. A 20 mm round causd a major gash in the Variable intake slide and went straight down the engine throat, Blades bent all to hell. Went back to ops and ask the pilot nicely to come back to the bird. He complied and upon arrival requested him to don a B Suit and go up the ladder and crawl down to observe the problem. Did not explain before what the problem was. He came back down and I inquired did he have any idea of how the proplem may have occurred. On the straffing range he stated? Knew from past experience at Wheelus that off the range there was a armoured column from WW11 that the blowing sand covered and uncovered. Past experience and other pilots told me they like to see the “SPARKLE” as the shells richoted off the vehicles. Wrote off in my stupidity as an “FOD”. Never reached out to Flight Safety. “STUPID’ on my part. In 65” a bird came back from the range with a neat 20mm hole in the bottom of the radar dome. Did a # on the radar dish/mounts and etc but did NOT exit. Pilot stated must have occurred on the range. As each dome was handfitted shipped back to Seymour for repair. Again in infinite “STUPIDITY” did not have the Flight Safety officer do a report. Funny seeing the bird on thre ramp for like 2 weeks with no dome.
Hard to believe this first flew nearly 70 years ago! Great plane.
Great aircraft.
My dad worked at Republic-Fairchild for 35 years, F-84/F-105/A-10.
Remember going to Republic at a family and day seeing the ‘105s on assembly floor and thinking, that’s a really big airplane for just one guy.